Humans

The most populous and powerful species in the Mjolner galaxy. Humans are a mammalian species of mostly hairless bipedal primates with a higher than average intellect. Humans are aliens to the Mjolner galaxy at large, arriving en masse into the galaxy in vast numbers in tremendous colony ships. They began a mass exodus of their original homeworld of Earth, a planet quickly deteriorating as a result of their massive population explosion. Soon after claiming the planet of Homeworld, a beautiful garden world with conditions almost identical to the original conditions of Earth, and interestingly enough, entirely uninhabited by alien sapient life.

It was from here that humans began to build from, spreading to the furthest stars of this new galaxy and colonizing dozens of worlds. However, humanity quickly tired of being forced to share the galaxy with aliens (or rather, it's original inhabitants). Tensions began to rise between humanity and the rest of the galaxy's races, although nothing would come of it until a man known as Mathias Longfellow took advantage of mankind's hatred of aliens, spurning the cries of war.

It was here that humanity, already mistrusted by most species in the galaxy, gained it's reputation as an imperialistic species of conquerors. Humanity began a massive war against the other species, which were crushed easily by the human weapon of war, the HMV. In the span of this conquest, humans displaced millions of aliens, rendering much of them virtually extinct and enslaving most of the ones that were not. Soon enough, humanity was ruled by a central government known only as the Empire and asserted it's place as most powerful race present in the Mjolner galaxy, with only few alien species still retaining their independence.

However, while the Empire is the most notable and most infamous of the factions that make up humanity, it's by no means the only. Soon after it established it's presence in the galaxy, humans began fracturing, carving up different segments of the galaxy to call their own. Isolating themselves, fighting amongst themselves or simply trading with the few independent alien species that still remain in the Empire.

Soon after mankind took it's place as most common species in the Mjolner galaxy, they began devolving into infighting. Rebellions like the Hydra League began a massive, still continuing war against the Empire, incensed at the Empire's anti-alien, isolationist policies collapsing many planets' alien export reliant economies.